Evaluation of tissues for the presence of cancer cells on abnormal tissues is an important and crucial step in the diagnosis, disease management and control of cancer. We have generated a mouse monoclonal antibody which detects a glycolipid antigen (PAA) on proliferating T- cells, B-cells and tumor cells in both frozen and paraffin fixed tissues. We hypothesize that level of binding of this antibody to a cell reflects its proliferation potential. We will test this concept in a series of experiments which include in situ comparative immunohistochemical staining of proliferating cells in lymphomas and a variety of solid tumors with anti-PAA monoclonal antibody that is used to stain proliferating cells in frozen sections of normal and cancer tissue. We will use digital image analysis and immunofluorescence staining for the in situ studies. The results of these studies will determine the feasibility of using anti-PAA monoclonal antibody as an immunodiagnostic reagent for detection of proliferating cells in tumors.